Cam mechanism for wood-screw machines.



H. 1.- SMITH.

CAM MECHANISM FOR WOOD SCREW MACHINES. APPLICATION mzu SEPT- 11. ms.

Patented Aug. 29, 1916'.

ms nonms PETERS m. Pnomurno" wAsnmo re". a c.

HENRY L. SMITH, OF WATERBURY, CONNECTICUT, ASSIGNOR TO Tit-IE E. J. MANVILLE MACHINE COMPANY, OF VVATERBUBIY, CONNECTICUT, A CORPORATION OF CON- NECTICUT.

CAM MECHANISM FOR WOOD-SCREW MACHINES.

Application filed. September 17, 1915.

all whom it may concern:

3e it known that I, HENRY L. SMITH, a citizen of the United States, residing at Waterbury, in the county of New Haven and State of Connecticut, have invented a new and useful Improvement in Cam Mechanism for lVood-Screw Machines, of which the following is a specification.

In automatic wood-screw machines the thread cutting tool is fed back and forth several times for cutting the thread on each lank. .lEaeh time the tool feeds forward it is moved in a little more than during the previous forward feed so as to increasethe depth of the cut, and, of course, after each forward feed it is thrown out away from the blank so that it may be returned.

This invention relates to mechanism which is provided for causing this increase in the depth of the successive cuts and throwing out of the tool to permit its return movement.

The cam which controls the depth of the cuts has to be changed for different sizes of screws, consequently is arranged so that it can be conveniently removed.

The object of this invention is to provide a depth cutting means which is more durable, has greater holding power, has larger range of adjustment, is more easily manipulated for substituting one cam for another, and is more efficient than prior mechanism designed for this purpose.

in the accompanying drawings so much only of an automatic wood-screw machine is shown as is necessary to illustrate the present improvement.

Figure 1 is a front elevation of one end of a machine of a common type showing the mechanism for controlling the depth of the out of the threading tool. Fig. 2 is a side elevation of the same. Fig. 3 is a face view on larger scale of the depth cutting cam. Fig. f is a section of the cam on the plane indicated by the dotted line li on Fig.

The threading tool 1 is clamped in a holder 2 that is mounted on the threading tool shaft 3 which is supported so that it may be oscillated and also reciprocated in bearings held by the uprights 4- of the machine frame. Mounted on the threading tool shaft is a lever 5 which has an adjustable profile shoe 6 that, as the shaft with the Specification of Letters IPatent.

Patented Au: 29, 1916.

Serial No. 51,175.

threading tool and lever is reciprocated, travels along the face of the profile plate 7, which, through the shoe and lever causes the shaft to rotate to give the cutting tool its different in and out positions.

The profile plate is adjustably clamped to the front part of the profile lever 8 that is pivotally hung between the frame uprights on bearings through which the threading tool shaft passes. The rear end of the profile lever is held in engagement with the periphery of the depth cam 9. This cam is a segment of a ring or a yoke-shaped piece with projections 10, 11, 12, 1.3, 14- and 15 on its periphery that are the result of cutting away intermediate sections of the outer edge. These projections are of increasing height so as to throw the threading tool holder a little farther in at each cut. Extending inwardly from the cam ring is an internal tongue 16 that is designed to be clamped be tween the outer edges of the collars 17 and 18. The collar 17 is rotarily fastened to the cam shaft 19 by a key 20 and is held against longitudinal movement thereon by a setscrew 21, whereas, the collar 18 is only rotarily fastened to the shaft 19 by the key 20, this collar being slidable along the shaft.

Screw bolts 22 extend through smooth perforations in the collar 17 and turn into threaded perforations in the collar 18 for drawing the latter toward the former and clamping the cam between them. The cam is cut away on one side so that when the screws are turned in such manner as to loosen the grip of the collars it can be withdrawn from between them. hen the screws are tightened the loose collar is drawn up so as to clamp the cam tongue between the collars and hold it securely. Before the screws are tightened the cam can be accurately adjusted in any position about the shaft and when the screws are tightened the cam is very strongly secured in its properrelation to cause the desired movements of the threading tool. With this construction a cam can be quickly removed and another substituted and the range of adjustment is unlimited. The collars hold the cam firmly in accurate position. The profile lever is forced down more and more by each projection on the periphery of the cam so that each succeeding cut of the threading tool will be deeper than the preceding cut, the end of the profile lever dropping into the recesses between the projections when the tool is returned and dropping into the space where the cam is omitted during the time that a blank is being fed to the spindle jaws which held it while it is being threaded. Vhen the lever drops off the cam it rides on the collars and is supported on both sides so that it will be properly retained and the Wear will be uniform.

The invention claimed is;

1. The combination in a wood-screw machine of a cam shaft, two perforated collars mounted on the shaft, a key rotarily connecting the collars with the shaft, means longitudinally fixing one of the collars on the shaft, a yoke-shaped cam having its outer edge formed with projections of successively increasing height and its inner edge extending between the outer edges of the collars, and screws passing through the collars but not through the cam for drawing the collars together and clamping the inner edge of the cam between them.

2. The combination in a wood-screw machine of a cam shaft, a collar with plain perforations rotarily and longitudinally fixed on the shaft, a collar with threaded perforations rotarily fixed but adjustable along the shaft, a yoke-shaped cam having outwardly extending perforations of successively increasing height on its outer edge and an inwardly extending annular tongue on its inner edge, said tongue lying between the outer edges of the collars, and screws passing through the plain perforations in the longitudinally fixed collar into the threaded perforations in the longitudinally adjustable collar but not through the cam for drawing the movable collar toward the fixed collar and clamping the cam tongue between them.

HENRY L. SMITH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, t3.- 

